The third paragraph was about the “different Englishes” she uses. She was giving a talk about her book and she was using different terms that she doesn’t use with her mother. What she meant by different Englishes is a different way of speaking it. She still speaks English with her mother but just in a way she can understand.
In the fourth paragraph, Amy uses the English she uses with her mother and her husband didn’t notice it. She says “Its because over the twenty tears we’ve been together I’ve often used that same kind of English with him, and sometimes he even uses it with me. It has become our language of intimacy, a different sort of English that relates to family talk, the language I grew up with”. When you spend so much time with someone you don’t notice the things you did before because you get used to it.
“Some say they understand none of it, as if she were speaking pure Chinese. But to me, my mother’s English is perfectly clear”. Some people might not be able to understand because of their accent. But for Amy, that grew up with her mother she might not hear an accent and she does understand her.
“The fact that people in department stores, at banks, and at restaurants did not take her seriously, did not give her good service, pretended not to understand her or even acted as if they did not hear her”. I find this crazy and unfair how they treat someone differently just because of their “broken” English.